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Evolución reactiva de la HMML desde la formación en fase gaseosa hasta la transformación de la interfaz en aerosoles
Xihong Liu1, Baozhong Zhang1, Xiaohui Ma1
1School of Environmental Engineering, Henan University of Technology, Zhengzhou, Henan 450001, China.
The journal of physical chemistry. A
|September 5, 2025
Resumen
El hidroximetil-metil-α-lactona (HMML) se forma a partir de la oxidación del isopreno. Su transformación en aerosoles ácidos, influenciada por la concentración de ácido sulfúrico, dicta la composición de aerosoles orgánicos secundarios (SOA).
Área de la Ciencia:
- Química de la atmósfera
- Ciencias del medio ambiente
- Química Física
Sus antecedentes:
- La oxidación del isopreno contribuye a la formación de aerosoles orgánicos secundarios (SOA).
- El hidroximetil-metil-α-lactona (HMML) es un intermediario crucial en el SOA derivado del isopreno.
- La transformación de HMML en condiciones de aerosol ácido sigue siendo poco conocida.
Objetivo del estudio:
- Investigar la formación de HMML a partir del peroxinitrato de metacriloilo (MPAN).
- Elucidación de los mecanismos de transformación de HMML en las interfaces de aerosoles de ácido sulfúrico.
- Determinar la influencia del microambiente del aerosol en el destino de la HMML y la producción de AOS.
Principales métodos:
- Cálculos químicos cuánticos
- Simulaciones de dinámica molecular de Born-Oppenheimer (BOMD)
- Simulaciones de metadinámica (MTD)
Principales resultados:
- La adición de radicales OH al carbono β del MPAN forma HMML a través de una reacción concertada.
- El HMML se adsorbe de manera estable en aerosoles ácidos a través de la unión de hidrógeno.
- El HMML se convierte en ácido 2-metilglicérico (2-MG) o sulfato de ácido 2-metilglicérico (2-MGOS) dependiendo de la concentración y solvación del ácido sulfúrico.
Conclusiones:
- Los microambientes interfaciales de aerosoles controlan de manera significativa las vías de transformación de la HMML.
- La concentración de ácido sulfúrico determina si el 2-MG o el 2-MGOS es el producto dominante.
- Comprender el destino de HMML es vital para el modelado preciso de la formación de SOA y la química multifásica atmosférica.
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